1. Field of the Invention
This invention relates to a semiconductor memory, and particularly to a serial access memory that can be used in image processing and operated at a high speed.
2. Description of the Related Art
A serial access memory has been widely used for image processing in personal computers, word processors and the like. The serial access memory employed in image processing needs a high image-drawing speed. To meet such a demand, a device is normally used wherein a serial access memory is electrically connected to a general-purpose dynamic random access memory (hereinafter called a "DRAM"). This type of device writes data into the DRAM and thereafter reads data corresponding to a desired row, one row at a time. Then, the read data are transferred to the serial access memory, from which the data are serially read.
This type of serial access memory has been disclosed in Japanese Patent Application Laid-Open Publication Nos. 2-105388 (Laid-Open Date: Apr. 17, 1990) and 3-76091 (Laid-Open Date: Apr. 2, 1991).